It probaby depends on where you go snorkeling. My husband is not a small man and the vests fit him fine. We have been snorkeling in St. Thomas, Nassau, and Mexico (all of the places we went required the life vests). FYI you might want to take some biodegradeable sunblock. If you are snorkeling coral reefs or in some places like XCARET they won't let you in with any other kind. Hope this helps.

Some of the ships are easier to get on and off when they have dive platforms, but none of the catamarans have had them. It is easier getting into the water than out, but if you have someone you can hand your equipment to on board you should have no trouble getting out. We've snorkeled in St. Thomas, St. Kitts, Grenada, Mexico, Grand Cayman, Barbados, St. Maarten, Martinique, St. Vincent, Curacoa, Bon Aire, Aruba, Tortola, Domiica, Jamaica, and a few other places which have all required snorkel vests. They're pretty adjustable, so I doubt you'll have any problems. Enjoy your cruise and snorkeling!!

My big guy, had no problem with the vest or the ladder. We were lucky to be on a boat with a dive ladder though so it was just a matter of walking down the steps. More trouble for me as I'm vertically challenged and I had a hard time reaching the bottom step to get back on the boat.

In Cozumel, we took one of the catamarin's for snorkle, and they had the ladder down the front and it was no problem either getting off or on.

How big are your BIG GUYS.. and how adjustable...what size chest do they fit....or whatever....any help would be great...just don't want to waste my time...doing it if the vest isn't going to fit...
as for getting in and out of the water i am very limber for a biggggger guy....that doesn't bother me.....its just the size of the vest etc.

Being a big guy was not a problem. The only thing I can suggest is if you have a mustach, shave it off. I had a problem getting the mask to seal over it. We have done the catamaran smorkeling trips twice. They both had a drop down staircase that was easy to get on and off.